A source told the newspaper that the procedure is minor and elective. Pietrangelo is expected to be ready for the start of training camp Sept. 21.

Alex Pietrangelo is expected to be ready for the start of training camp. (AP Photo)

The Post-Dispatch noted that the 22-year-old suffered a sprained knee during Game 1 of the Western Conference semifinals last spring and sat out Game 2. At the time, Pietrangelo told reporters that surgery would not be required, and it was unclear Monday whether the upcoming procedure is related to that injury.

Pietrangelo played in 81 regular season games for the Blues in 2011-12 and set career highs with 12 goals (six power play goals), 39 assists and 51 points.